Area Forecast Discussion
Issued by NWS Charleston, WV-- Highlight Changed Discussion --
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FXUS61 KRLX 281118
Area Forecast Discussion
National Weather Service Charleston WV
618 AM EST Tue Feb 28 2017
An upper disturbance brings showers and possibly a thunderstorm
today. Strong cold front passes Wednesday. Reinforcing
trough/front Thursday night. High pressure for the weekend.
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --As of 6 AM Tuesday...
Adjusted pops faster in the west this morning per latest radar
trends. Do not think thunder will make it this far east early
this morning, as deeper instability is lacking. Main batch of
showers and possibly thunder still to come across later in the
As of 3 AM Tuesday...
Within a broad and vigorous southwest flow aloft, models key in
on an upper level disturbance moving over a warm and
increasingly moist atmosphere today. This brings a widespread
band of rain showers today, mainly from later this morning
through this afternoon. Deep instability is still lacking with
this feature, so have only a slight chance for thunder.
Nevertheless, rainfall amounts from a quarter of an inch up to
as much as three quarters of an inch in spots can be expected.
Temperatures will be much above normal in the low level
southerly flow, despite the clouds and showers.
For tonight, expect a break in the rain before another upper
disturbance comes our way later tonight. This will initiate
more showers, and a better chance of thunderstorms as the
atmosphere further destabilizes. However, the chance for any
severe thunderstorms will mainly come just after this period as
better parameters will then be in place. With a southerly flow
and clouds, temperatures will be on the mild side tonight.
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.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
As of 240 AM Tuesday...
Will mostly likely have a squall line in progress pushing
towards the Ohio Valley at the break point from the near term
forecast. Have multiple ingredients in place for a severe setup.
Very dynamic situation with strong shear profiles pushing 90kts
0-6km values with falling heights aloft from the approaching
trough. Strong surface front in place from a deepening center of
low pressure. Still have 10C dewpoints to work with at 850mb and
near 60F dewpoints at the surface which may increase slightly
with some pooling ahead of the front. SPC has the risk
increased to enhanced across the bulk of the CWA. Damaging wind
threat exists, and cannot discount hail given the colder air
aloft. Also have potential issues with excessive rainfall as
given the PWAT values well over an inch.
Behind the front, will turn sharply colder as the moisture
exits. Lingering precipitation will transition to rain/snow mix
and all snow in the higher elevations. Have a storm total snow
grid in place, but only minor accumulation well under an inch
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 240 AM Monday...
Reinforcing cold front/upper trough combo passes Thursday night,
but will only keep the cold air in place for so long. Some light
snow at night will accompany the system. Rebounds to above
normal values expected Saturday, increasing through the Monday
time frame with strong 850mb ridging returning with high
pressure settling in at the surface.
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --12Z Tuesday thru 12Z Wednesday...
As of 6 AM Tuesday...
For Today, a wet upper disturbance will move eastward across
the area. Clouds will lower and thicken rapidly from west to
east with widespread showers accompanying this disturbance. Deep
instability is marginal for thunder, so included just a slight
chance today with the showers. Look for VFR ceilings becoming
MVFR ceilings and VSBY in the precip, but brief IFR cannot be
ruled out. South winds generally 5 to 10 KTS.
The showers will exit the mountains this evening with the
disturbance. MVFR conditions are expected to continue behind the
departing system with the lingering low level moisture, but
again IFR cannot be ruled out and will have to be monitored.
South winds generally 3 to 7 KTS increasing after 06Z to 10 to
15 KTS with higher gusts. Look for rain showers to also increase
after 06Z from west to east with another disturbance.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: There may be more IFR this afternoon in
the rain, but especially this upcoming night with lingering low
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 02/28/17
UTC 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
EST 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16
CRW CONSISTENCY H H H H H H H H H M L L
HTS CONSISTENCY H H H H H H H H M M L L
BKW CONSISTENCY H H H H H H H H H H L L
EKN CONSISTENCY H H H H H H H H H H L L
PKB CONSISTENCY H H H H H H H H H M L L
CKB CONSISTENCY H H H H H H H H H H L L
AFTER 12Z WEDNESDAY...
NO WIDESPREAD IFR CONDITIONS ARE EXPECTED AT THIS TIME.
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